In copying or reproducing three-dimensional surfaces, heretofore, the conventional technique involves the recording of images of sections of the surface, which are illuminated by a plane of light directed against the surface. The images are recorded of the sections where the plane of light intersects the surface. The plane of light is produced by a projector which directs the light against the surface.
In carrying out the conventional methods for reproducing three-dimensional surfaces, the camera which views the surface and records the intersections of the plane of light and surface sections, is displaced from the projector or the light plane. In practice, the camera is at a substantial angle to the light plane.
When the optical axis of the camera is substantially perpendicular to the light plane, it is possible to locate a surface point and record it on the camera film with particularly high accuracy. However, when that angle is substantially small, substantially poor accuracy is incurred in locating a point on the surface of the object to be reproduced.
Copying systems for reproducing three-dimensional surfaces are conventionally constructed so that small angles prevail between the optical axis of the camera and the light plane, because hidden areas or holes cannot be viewed by the camera when large angles prevail. Thus, shadow effects are present when the reproduction system possesses large angles between the optical axis of the camera and the light plane.
When using such small angles in conventional systems, the camera focus is not suitable for all points of the three-dimensional object surface. Thus, if the camera focus is set for one given point of this surface, the focus cannot be expected to be properly set for other points of a general three-dimensional surface. As a result, the focus is required to be continuously adjusted in conventional systems.
Accordingly, it is an object of the present invention to provide an arrangement in which the camera focus may be set so that it is in proper focus for substantially all points of the surface to be recorded, without having to readjust the setting of the focus for differently located points on the surface.
Another object of the present invention is to provide an arrangement of the foregoing character which is substantially simple in construction and may be economically fabricated.
A further object of the present invention is to provide an arrangement as described, which may be readily maintained in service with substantially long operating life.